Field of the Invention
The present invention relates to a light-emitting unit having Group III nitride semiconductor light-emitting devices.
Background Art
Semiconductor light-emitting devices have been applied to the field of optical communication or optical information processing using optical fiber module in addition to illumination use. When the semiconductor light-emitting device is applied to optical communication or the like, the light-emitting device is desired to have a good responsiveness after the power is turned on until the light is emitted, and a high light output.
Thus, there have been developed semiconductor light-emitting devices having a good responsiveness. For example, Japanese Patent Application Laid-Open (kokai) No. 2002-314130 discloses a light-emitting diode which uniformly emits light even when the light emitting area is very small. An electrode material is selected so that the ohmic characteristics of the transparent electrode for the p-type semiconductor layer are superior to the ohmic characteristics of the p-side diffusion electrode for the p-type semiconductor layer (refer to paragraphs [0007], [0028] to [0029]).
However, the light emission quantity tends to be insufficient when the light emitting area is very small as described above. Recently, a light emitting-device having more remarkable responsiveness is expected.